A key difference separates the dramatic teen fantasy "Before I Fall" from the comic adult fantasy "Groundhog Day," which critics will doubtlessly compare it to the most.

In the latter, Bill Murray's nasty weatherman relives the same day over and over until his bitter soul learns that empathy and self-improvement can sustain a life for eternity.

In the former, "Vampire Academy" star Zoey Deutch's high school teen Samantha Kingston relives the same day over and over until she learns the lesson of Anne Frank: despite everything, people are really good at heart.

But they let ego and superficial concerns clog good hearts and they become distracted from life's important things.

"Before I Fall," Ry Russo-Young's visually stylish adaptation of Lauren Oliver's popular novel, challenges teen audiences to become the good people they truly are.

Perhaps not trusting the target demo to get this from just the story, Russo-Young lingers on a poster saying, "Become the person you truly are."

Three times.

We spend the first pleasantly monotonous day (Feb. 12) with Sam in her super-upscale community. She is rude to her cute little sister and her even cuter mother (Chicago's Jennifer Beals).

Sam hooks up with her privileged, snooty female rat pack -- two of whom barely possess personalities -- led by the highly critical Lindsay (Halston Sage).

At school, Sam celebrates "Cupid Day" with classmates, among them Kent (Logan Miller). He loves Sam from afar, but she shuts him down.

She goes along with the cruel public ridiculing of Juliet (Elena Kampouris), a social outcast targeted by Lindsay.

At night, they go to Kent's house for a party. Sam intends to lose her virginity to self-centered boyfriend Rob (Kian Lawley), if he can stay sober.

This part of the movie moves with slow deliberation as Maria Maggenti's screenplay sets up a baseline for what happens on this day, one that will be repeated for an eternity after a mysterious car crash kills Sam and her friends later.

Sam wakes up in the morning to do it all over again.

The supernatural forces behind "Before I Fall" are never explained (as they remain a mystery in "Groundhog Day"). The story reinforces the Genie's advice to Aladdin to "Bee yourself" with a strong anti-bullying theme.

Yet, the movie's enigmatic ending proves to be a bit of a thematic head-scratcher.

Russo-Young keeps the many Feb. 12ths fresh enough to preserve our interest. It doesn't hurt that the disarming Deutch mindmelds with Michael Fimognari's camera lens so we can see the good pulsing under Sam's teen facade of cruel coolness and dismissive narcissism.

Miller emanates an appealing aura of sincerity as Kent, a thin character who gradually grows on us, as he does Sam.

As Lindsay, Sage handles the heavy lifting in this cast, giving what could have been a one-dimensional B-queen a vulnerable, frightened interior protected by layers of meanness and antagonism.

"Maybe for you there is a tomorrow," Sam tells us in voice-over narration. "Maybe there is 1,000."

And maybe during her endless English classes, she can learn when to use "are" instead of "is."